Vehicle braking systems include braking actuators (hydraulic or electromechanical) for applying a braking torque to the wheels of the vehicle tending to slow the vehicle down.
Most brake controllers known in aviation make use of a setpoint that is converted either into a pressure for hydraulic brakes or into a force for application or into a displacement of a pusher when using brakes with electromechanical actuators.
Controllers have also been proposed that make use of a torque setpoint and that organize their feedback loops on the basis of the measured torque, as described in document US 2005/0001474. Those controllers present the advantage of taking overall account of the action of the brake via the torque control generated thereby, making it possible to adapt to dispersions in brake torque responses for a given braking force.
Nevertheless, those controllers using a large passband can interfere with the anti-locking protection of the wheels, in particular when there is a phase difference between the torque commands and the anti-locking commands. Under certain grip conditions, torque control delivers a torque setpoint that is temporarily zero in order to prevent the wheels locking. However if the wheel locks in untimely manner, then the measured torque disappears suddenly and the measured torque is then equal to the zero torque setpoint. The wheel therefore remains locked, without the brake being controlled to release the wheel.